W-CDMA has been standardized as a third generation cellular mobile communication scheme by 3GPP (3rd Generation Partnership Project), and services based thereon have been sequentially launched. Also, HSDPA with higher communication speed has been standardized, and services based thereon have been launched.
Also, in 3GPP, standardization of evolved third generation radio access (Evolved Universal Terrestrial Radio Access, hereinafter referred to as “EUTRA”) is progressing. As a downlink communication scheme of EUTRA, OFDM (Orthogonal Frequency Division Multiplexing) is employed which is robust against multipath interference and is suitable for high-speed transmission. As an uplink communication scheme of EUTRA, DFT (Discrete Fourier Transform)-spread OFDM, which is SC-FDMA (Single Carrier-Frequency Division Multiple Access) and which can reduce the PAPR (Peak to Average Power Ratio) of a transmit signal, is employed while taking cost and power consumption of mobile station apparatuses into consideration.
Moreover, in 3GPP, discussions over Advanced-EUTRA which is further advancements for EUTRA have begun. Advanced-EUTRA assumes communications at a downlink peak transmission rate of 1 Gbps or higher and at an uplink peak transmission rate of 500 Mbps or higher by using a band having a bandwidth of up to 100 MHz in each of the uplink and the downlink.
It is conceived that a band of up to 100 MHz is realized in Advanced-EUTRA by aggregating a plurality of EUTRA bands, each of which has a bandwidth of 20 MHz or less, in order to support EUTRA mobile station apparatuses. In Advanced-EUTRA, each EUTRA band of 20 MHz or less is called a “component carrier (CC)” (NPL 2 described below). One downlink component carrier and one uplink component carrier constitute one cell. Note that one downlink component carrier alone can constitute one cell. The base station apparatus assigns a plurality of cells to each mobile station apparatus and performs communication with the mobile station apparatus via the assigned cells.